Descrizione

Elenco dei parametri

stream

The target stream.

filtername

The filter name.

read_write

By default, stream_filter_prepend() will
attach the filter to the read filter chain
if the file was opened for reading (i.e. File Mode:
r, and/or +). The filter
will also be attached to the write filter chain
if the file was opened for writing (i.e. File Mode:
w, a, and/or +).
STREAM_FILTER_READ,
STREAM_FILTER_WRITE, and/or
STREAM_FILTER_ALL can also be passed to the
read_write parameter to override this behavior.
See stream_filter_append() for an example of
using this parameter.

params

This filter will be added with the specified params
to the beginning of the list and will therefore be
called first during stream operations. To add a filter to the end of the
list, use stream_filter_append().

Valori restituiti

Returns a resource which can be used to refer to this filter
instance during a call to stream_filter_remove().

Log delle modifiche

Note

Nota:
When using custom (user) filtersstream_filter_register() must be called first
in order to register the desired user filter to filtername.

Nota:
Stream data is read from resources (both local and remote) in chunks,
with any unconsumed data kept in internal buffers. When a new
filter is prepended to a stream, data in the internal buffers,
which has already been processed through other filters will
not be reprocessed through the new filter
at that time. This differs from the behavior of
stream_filter_append().

Nota:
When a filter is added for read and write, two instances of the filter
are created. stream_filter_prepend() must be called twice
with STREAM_FILTER_READ and
STREAM_FILTER_WRITE to get both filter resources.